1. Field of the Invention
The present invention generally relates to storage devices including non-volatile memory that maintain data after a power source is shut off, and more particularly to a storage device that can execute a test process based on a test signal output from a test terminal while maintaining high security.
It is important to maintain high security for data stored in the storage device. It is also important to improve the quality of the storage device.
To improve the quality of the storage device, it is required to test for failures in storage devices after assembly is completed. Generally, it is needed to provide a test terminal to test the storage device. However, the provided test terminal makes it possible for outsiders to easily obtain data such as a cipher key or secret data stored in the storage device.
Consequently, it is desired to not only realize higher security but also develop a technology to test fully assembled storage devices.
2. Description of the Related Art
For example, a non-volatile storage device such as a memory stick is used to record an encrypted copyrighted product such as music.
In a case in which the test terminal is provided for the storage device, when the cipher key is read by an illegal user, the copyrighted product may be easily pirated.
Further, an authentication is processed based on cipher text by using a shared cipher key between the non-volatile memory and a host device for use thereof.
Disadvantageously, in this case, when the cipher key is read, a host device used by the illegal user can obtain data from the non-volatile memory by utilizing the test terminal.
Accordingly, the test terminal is not conventionally provided for the non-volatile memory so as to prevent a cipher key or secret data from being stolen by utilizing the test terminal and the test function.
In the above conventional non-volatile memory, illegal users' infringement can be prevented and high security can be maintained.
However, makers manufacturing conventional non-volatile memories can not properly test fully assembled non-volatile memory to ensure the quality thereof.
In the conventional manner, it is difficult to improve the quality of the non-volatile memory.